how do you bleed motorcycle brakes?

Question

I had to replace the front brake line so I need to know how to pump new brake fluid in the front brake line on my motorcycle.

Answer 1

1) Fill the master cylinder.
2) Apply brake
3) Open bleeder (small hex nut on calliper that looks like zirc fitting)
4) Close bleeder.
5) Release brake.

Repeat steps 2-5 until no air comes out bleeder.

You may have to top off the master cylinder a couple times during the process. Don't let it get empty while you're bleeding the system. And don't get any brake fluid on the paint. You can put a small hose on the bleeder and place it in a container, or put a rag over the bleeder to capture the fluid that will spray out of it when the valve is opened.
Good luck

Ride safe

Answer 2

yep, what they said but it's hard to get all the air bubbles out by merely pumping the lever and bleeding the valve on the caliper. take a screwdriver or something similar and tap on the lines while you are pumping the lever. also make sure you are applying pressure to the lever when you open the bleed valve or otherwise you will suck more air into it making it a never ending process.
-=-=-=-=-=-=-
it also helps if you can find a large syringe to use with a rubber/plastic tube epoxied or zip tied to the syringe, put on bleed valve and fill the lines from the bottom. this forces all the air to rise up to the main reservoir.
-=-=-=-=-=-
another idea that works well is this will help you today and the next time you need to change your fliud or just bleed your brakes. see diagram on how to make a bleeder.

http://www.texasoffroad.net/files/184539-Scan04-06-26%202121.JPG

It is a 20oz. bottle with a clear tube epoxied into the top with a loop in the hose. use zip-ties to hold the hose together to make the loop.

the hose needs to fit tightly onto the bleeder valve opening. take the cover off the reseviour and open the bleeder valve. start pumping the brake, but keep a good level in the reseviour. Do this until you have completely flushed out the resevour and the hose. Close the bleeder valve, put the cover back on and then check your brakes, if they are tight you are done, if not repeat.

This is the "one-man way" to bleed you brakes the easy way. And it works great on the line; you can bleed your brakes in less than a minute.

Good luck!!!

Answer 3

When I installed braided stainless lines on my Kawasaki, I too had a very hard time getting all the air out. First off, vacuum pumps work great for automotive disc brakes, but for bike disc brakes and old style automotive drum brakes, they pull air past the brake piston seals and you never get all the air out. I have one and like anything, there's a time and place for it but not on bikes and antique cars. First off, with a hose on the bleed screw at the calipers, open the screw one at a time and compress the calipers one at a time until you have the pistons pushed all the way in. This will expell as much air as possible. Then slightly loosen the banjo bolt at the mastery cylinder. Holding a large wadded rag beneath it, loosen the bolt maybe 1/4 turn and pull the lever back all the way until fluid flows out of the banjo bolt. Tighten the bolt and then go down to the T fitting. With a clean rag (you don't want to use the old rag and drip brake fluid onto the fender), do the same with the other end of the line coming from the master cylinder. Then do both of the other fittings on the lines going to the calipers. Then move down to the calipers and with a hose on the bleed screw, open the screw a bit, squeeze the brake lever and while you're holding it back close the screw. Release the brake lever and repeat it over again until no bubbles appear and then go to the other one. This should expell all of the air. If it still seems a bit spongy, try parking the bike out in the hot sun all day and see if that helps. That's what it took to get all of the air out on my Kaw.

Answer 4

The same way you bleed automobile brakes - like Scooter Trash said.
If you can't find a hose to fit on the bleeder valve, use the battery overflow tube (if your bike has one) - perfect diameter and clear to see when the air bubbles stop coming out.

Answer 5

MityVac is the only way to fly.
You draw fluid from the master cyl, straight through the bleeder and as long as you don't let the master cyl go empty, you pull all the air out .

Answer 6

Stab 'em and watch 'em bleed ... BWAHAHAHAHAHAHA!

Sorry. I think there should be a bleed valve down by the brake calipers that you twist. Open the bleed valve, fill with fluid, and when there's no more bubbles coming out of the valve close it.

Answer 7

go to bike shop and get yourself a mghty vac brake line bleeder.makes for a perfect job.

Answer 8

pmk is right.
The only thing I can add is to get one of these:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474

these:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92924

or these:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39522